Lift truck



May s, 1942.

J. J. NEUMAN LIFT TRUCK Filed Oct. 18, 1940 4 Sheets-Sheet 1 GttornegMay 5, 1 942 v J. J. NEUMAIN 2,282,201

LIFT TRUCK l J. J. NEUMAN -May s, 1942.

LIFT TRUCK Filed oct. 18, 1940 4 Sheets-Sheet 3 :inventor Lf. elw/@ummGttorneg J. J. NEUMAN May 5,l 1942.

LIFT TRUCK Filed 001'.. 18, 1940 4 lSheets-Sheet '4 'wir Smaentor www .WEEE llalllllllll Ilcll.

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UNITED STATES PATENT v OFFICE LIFT 'muoril -Jacob J. Neuman, southsalem, N. Y., signor tu United States Patent Development and RoyaltyCompany, South Salem, N. Y. Application oete'ber 1s, 1940,-sem1' N0.361,176

11 emma. (o1. er1-113) high tiers due to the inability of the operatorfrom his position togauge the correct height `of the members in order toproperly enter `the pallet. He thus very often has the members too highor too low and they strike and break the edge boards.

Another source of breakage to the pallets has been due 'to failure ofthe operator. when pulling the members out, to lower them lsufficientlyor to lower them too much.

It has been attempted in the past to remedy these difliculties byprotecting the pallet edge boards with steel angles, sheet metal, etc.This made the pallets too expensive and not wholly satisfactory. Afurther attempt to solve the problem was by making the members blunt toprevent splitting of the pallet'boards and while this latter attemptimproved matters, the hard metal ends of the members still doconsiderable damage to the pallets.

It is an important object. of the present invention to provide loadcarrying members which will not he subject to the disadvantages abovementioned.

Another object of the invention is to provide the members with feelerand buffer means.

A still further object of the invention is to provide load carryingmembers which indicate to the operator of vthe truck when the membershave been correctly or incorrectly applied.

A still further object is to provide buffer means which are simple andinexpensive and which are easily applied and renewed. A

, With the foregoing and other objects in view,

the invention will be more fully described here- Figure 2 is afragmentary end view of the parts shown in Figure 1.

Figure 3 is a top plan view with parts broken away of the lifting memberwith the invention applied thereto.

Figure 4 is a side elevational view with parts broken away of the partsshown in Figure 3.

Figure 5 is a sectional view taken along the line 5 5 of Figure 3. 4

Figure 6 is a sectional view taken on the line 6 6 of Figure 3.

Figure 7 is a sectional view taken on the line 7 1 of Figure 3. l

Figure 8 is a top plan view with parts broken away of a lifting memberwith a modified form of the .invention applied thereto.

Figure 9 is a fragmentary top plan view of a lifting member with anothermodified formy of the buffer means applied thereto.

Figure 10 is a similar fragmentary top plan view with a still furthermodified form of the buffer means applied thereto.

Figure 11 is a side elevational view of the lifting means with thebuffer Vmeans shown in Figure 9 applied thereto and showing an improvedsupport for the lifting members.

Figure 12 is a cross-sectional view along the line I2-I2 of Figure 11.

Referring more particularly to the drawings and to the forms of theinvention shown by Figures 1 to 8 inclusive, the numeral lo designatesthe tip portion of a lifting fork .Il forming part of the lift truckdiagrammatically shown in Figure l. The lower face of the fork Il isgiven a taper I2 terminating in a beveled edge portion I3 while theupper face of the fork II, while not tapered, is provided with a bevelededge portion I4 similar tothat of I3, both of which are graduallyreducedto zero.

Between these beveled portions the edge of the fork is provided with asubstantially V shape channel I5 of varying depth as particularlyshown'by Figures 5. 6 and 7. Beginning at a point designated by lines 55 in Figure 3, the channel is at its greatest depth forming a pocketI I6and the channel gradually decreases in depth as designated by the line6-6 corresponding to Figure 6 until the minimum depth is at theoutermost edge of the tip portion I as designated by line 1-1 'andFigure 7. In referring to this channel of varying depth and to thevarious designations it is understood that the same variance is true onthe other side of the tip portion of member il although the sectionlines have not been applied thereto. The corners of the channel aresuitably rounded to eliminate cutting edges.

A section of standard V rope or other resilient material I1 if constantwidth but complemental in shape to channel l5 is arranged within thechannel to form buffer and-feeling means for the fork il. The ends i8 ofmaterial I1 are received in the deepest part or pockets I6 of thechannel and secured'to the fork il by clamping plates I9,

shake proof washers 20 and screws 2l, the latter o'f which are threadedinto fork vI I.

The pockets IB being the deepest portions of channel I5 completely housethe ends of the rope and their connecting elements to eliminate anyprotruding parts. In this manner the forks I I are not liable to beentangled in anything during their use or movement of the truck.

Accordingly the rope i1 from its attaching points in pockets I6 is givena gradually increasing areaof projection from the tip of fork EI. Thegreatest amount of rope projecting will be at the foremost portion ofthe tip ldue to the channel at this point being of the 'smallestidepthAs this `foremost portion is the one that initially y comes into contactwith the pallets, the greatest amountof protection is needed atthispoint.

It will be noted that the outer face of the V-shaped rope is sufficientto guard the beveled portions I3 and id of the fork II and this is forksIl on the elevating carriage' 29. This ar-A rangement is designed toprevent the damage to the pallets due to failure of the operator, whenpulling the forks vout, to lower them sumciently', orto lower them. toomuch. The vertical portion 3B of the fork Il is provided4 with a slot 3lthrough which a shaft or rod 32 extends. The rod l32 is journaled atboth ends in the elevating carriage 29 forming part of the truckdiagrammatically shown in Figure 1 of the drawings.

Each fork II is attached to the top of the elevating carriage 29 withsprings A33 of sufficient strength to support the weight of 'the forksii alone but not sumcient to support the forks when v they are carryinga loaded pallet. The connection of the upper ends of the springs 33 ismade with an eye bolt 33 and nut 35. The nut 351s so adjusted that whenthe forks Il are unloaded they are supported at a height Where the rod32 is at the midpoint ofthe slot 3l. It is thus seen that if the forksil are either slightly too high I. is provided with oppositely beveledrecessed porstantially U-shaped plate 31.

necessary to give the tip of thel fork a substantially all resilientcontacting surface.

The construction shown in Figure 8 is substantially the same as thatdescribed heretofore, the only difference being in the attachment of therope ends I8. In this modification the rope ends I8 are secured to thetip portion I0 by the same shake proof washers 20 and screws 2| ofFigure 3, the clamping plates22 in this instance being` any dam-age tothe pallet or 'its parts.

l Referring to the modification shown by Figure 9, a molded buffer 23having a radially projecting feeler ymember 24 is provided for the forkII. The manner of attachment of this -modication is similar to themanner of attachment described with reference to the buffer of Figures 1to 8.

In the modification shown by Figure .10 the resilient buffer iscomprised of two sections of rope 25, each rope section havinga radiallyextending y portion 26. 'Ihe extending portions 26 are joined togetherby rivets 21 to form a feeler member 28 similar to the feeler member 24of Figure 9.

The operation of the cxclmstruction shown by Figures 9 and 10 is of couvse similar to that de-` scribed in the' preceding' figures.

The feeler members 24 and 28 of these latter constructions enables theoperator to adjust the forks to the correct level before attempting toinsert the main forks. If the flexible feelers 24 and 28 'strikethe [5pallet boards no damage is done.

'tions 36 on its upper and lower face. These recessed portions 36 followthe contour of the fork and frictionally receive therein a slidable sub-The outer configuration of the plate 31 is arcuate to correspond withthe arcuate tip portion of the fork. A substantially V-shaped groove isprovided on the periphery of the plate 31 to accommodate a simi- I larspaced buffer, such as that shown at 23 in resilient contact surface ofthe buffer is not impaired. In order to accommodate the nuts 49 the forktip is provided with sockets di into which the nuts d@ will be receivedwhen the plate 31 has been forced to its limit within the i recesses 36.

The plate 31 is normally urged outwardly by means ofsprings 42 and 43disposed within a bore 44 formed in the tip ofthe fork I I. This bore 44extends from the edge portion of the tip and terminates in a housing 45at a point beyond the recessed portion 36. The diameter of the bore 44is larger at the tip portion than at its 'succeeding portions wherebyshoulders are provided in the bore. The spring 43 is encircled about arod 46 between two washers 41 and 48, the rod having a head portion 49.The rod isthreadedly secured to the 'central portion of the plate 31andthe washer 41 -bears against a shoulder portion of the bore 44whereby the plate and buffer are yieldingly supported. The spring 42 isdisposed within the smaller diameter of the bore 44 in contact with thehead 49 y-of rod 46 and the head 50 of a plunger 5I, The* In operation,when the buffer 23 strikes a pallet the. plate 31 and the rod 46 slideback, the

spring 43 is compressed pushing back the plunger I to operate the switch52. This switch being in the forward circuit of the driving motor of thelift trucis'` and when operated stops this motor and applies the brakes.The operator must then back the truck away and adjust the forks to thecorrect elevation. backed away the spring 43 returns the plate 31 tonormal position and the forward circuit of the lift truck driving motoris restored.

The length of the various springs and the plate 31 are so proportionedthat the truck will stop before the plate is pushed back to the limit ofits travel. The spring 43 is of a strength just sufficient to overcomethe sliding friction of the plate 31 and return it to normal positionwhile the spring 42 is even weaker being only of a strength to operatethe push button switch 52. It is thus seen that when the buffer strikesa pallet these springs give and no damage is done.

While it has been stated in all forms of the invention that the .buffermeans is preferably rope it is understood that any other type ofmaterial having inherent resiliency such as rubber may be substitutedtherefor.

The plunger 5I is rendered detachable from the head '50 or the switch 52in any suitable manner, such as screw threads or the like. This willpermit the plunger 5I to be first inserted in the bore 44 to be followedby the spring 42, rod 46 and spring 43. After these parts have beenassembled the switch 52 may be secured to the plunger 5l whereby thecomplete assembly is provided.

It is obvious that various changes and modifications may be made in thedetails of construcf tion and design of the above specifically describedembodiment of this invention without departing from the spirit thereof,such changes and modifications being restricted only by the scope of thefollowing claims.

What is claimed is:

1. In a lift truck, in combination, a frame, a lifting member carried byan end of said frame and adapted for insertion between the faces of `atwo faced pallet, said lifting member having a peripheral channel andpockets at the ends of said channel, a buffer element disposed in saidchannel to project beyond said lifting member, and'securing means forthe ends of said buffer element, said securing means and ends of saidbuffer element being wholly disposed within said pockets.

2. In a lift truck, in combination, a frame, a lifting member carried bysaid frame and adapted for insertion between the faces of a two facedpallet, said lifting member having a peripheral channel of variabledepth, said channel having its greatest depth at its ends to providepockets and its smallest depth at the tip porion of said lifing member,a buffer element disposed in said channel, said buffer element havingits vgreatest projecting portion at the tip of said lifting member,.theends of said buffer element being housed within the pockets of saidchannel, and securing means for the ends of said buer element secured tosaid lifting member within said pockets.

3. In a lift truck, in combination, a frame,

load carrying .members extending from said frame and adapted forinsertion between the faces of a two faced pallet, a channel on theperipheral portions of said lifting members, opposed deep pocketsdefining the ends of said channel, said channel progressively decreasingWhen the truck is and increasingt in depth between said pockets, abuffer element disposed in said channel, said buffer element havingprojecting areas corresponding to the channelv depths, and securingmeans for the ends of said buffer element, said securing means and endsbeing disposed within said deep pockets and secured to said loadcarryingmembers.

4. In a lift truck, in combination, a frame, load carrying membersextending from said frame and adapted for insertion between the faces ofa two facedpallet, a channel on the 'peripheral portions of said liftingmembers, opposed deep pockets defining the ends of said-channel, saidchannel progressively decreasing and increasing in depth between saidpockets, a buffer element disposed` in said channel, s'aid bufferelement having projecting areas corresponding to the channel depths, andsecuring means for the ends of said buffer element, said securing meansand ends'being disposed within said deep pockets and secured to saidload carrying members at an angle whereby said buffer element is drawninto said channel.

5. In a lift truck having a frame andan elevating carriage on saidframe, lifting members carried by said carriage and yieldable connectingmeans between said carriage and lifting members, said connectioncomprising a spring secured to said carriage and `to a vertical portionof said lifting members, said lifting members provided with an elongatedslot, a transverse rod in the slots and journalled to said elevatingcarriage, said yieldable connection normally biasing said members toraised position, and buffer means on said lifting members.

6. In a lift truck, in combination, a frame, adjustable load carryingmembers extending from said frame and adapted for insertion between thefaces of a two faced pallet, a channel on the peripheral portions ofsaid lifting members, a buffer element secured in` said channel andprojecting beyond said lifting members to form a resilient contactingsurface for the latter, and a flexible feeler member projecting fromsaid buier element.

load carrying members extending from said vframe and adapted forinsertion between the faces of a two faced pallet, a channel ofprogressively increasing and decreasing depth on the peripheral portionsof said lifting members, pockets formed by the greatest depth of saidchannel, buffer elements in said channel to progressively project fromthe lifting members in accordance with the depth of the channel, one endportion of each of said buder elements being secured in said pockets,the other end portions of each of said buer elements being connectedtogether to form a feeler member projecting beyond said buffer elements,and securing means recessed in said pockets for the first mentioned endportions of said buffer elements.

8. In a lift truck, in combination, a frame, load carrylng'members onsaid frame and adapted for insertion between the faces of a two facedpallet, a channel on the peripheral portions of said lifting members anda moulded buffer' element secured in said channel toproject therefrom.

9. In a power-driven lift truck, in combination,

a frame, adjustable load carrying members exto said load carryingmembers forming a resilient contacting surface for said members andnormally in projected position, said buffer element adapted to 'beinserted between the faces of the pallet, and being retractable uponstriking the pallet when said load -carrying membersare improperlyadjusted, and means carried by said lifting members for stopping theforward motion of said lift truck, said means adapted to be actuated bysaid buffer element when in retracted position.

10. The combination with a power-driven lift truck having a frame,adjustable load carrying members extending laterally from said frame andadapted for insertion between the faces of.

ment adapted to be inserted between the faces of the pallet, and meansfor yieldably maintaining said buffer element in extended position,whereby upon failure of said load carrying members to be properlyadjusted for lentry between the faces of the pa11et,said buler elementwill be retracted by striking the pallet to actuate said control means.

11. 'Ihe combination with a lift truck'having vertically adjustable loadcarrying members extending laterally therefrom and adapted for in'-sertion between the faces of a two-faced pallet;

of vbuffer means on the free ends of said load carrying membersprojecting ytherefrom and forming resilient contacting surfaces vforsaid load carrying members vto prevent damage to the palv. let'uponfailure of said load carrying members for actuating said control means,said butler ele- 20 to be properly adjusted, and feeler mea-nsprojecting forwardly from said buffer means.

' JACOB J. NEUMAN.

